In order to find conditions in which DC-targeted insulin peptide can alter diabetes pathogenesis, we have set up a series of tools and mouse models. We have created and produced chimeric antibodies that can target several insulin antigens to both DEC205+ and DCIR2+ DCs. In addition, we have optimized staining of MHC class II I-A-g7 tetramers with an insulin peptide for identifying insulin-specific CD4 T cells in vivo, and improved our pancreas and islet isolation to identify infiltrating T cells. We have also set up several mouse models in our lab, including the Insulin 2 knockout and heterozygous mice. Mice have 2 insulin genes, and because only Ins2 is expressed in the thymus, elimination of one or both alleles of ins2 reduces negative selection for insulin-specific T cells, resulting in accelerated diabetes in which the T and B cell responses are more insulin focused. We are now testing how chimeric antibodies that target insulin peptide to several DC subsets affects endogenous insulin-specific CD4 T cell responses, and diabetes pathogenesis (both insulitis and hyperglycemia).